I paid a family friend to lay a concrete patio attached to my back door. He laid it too high. Specifically flush with the back door. I know now this can be a big water issue but can’t imagine how to fix it. What are my options?

  • 2
    Flush with back door ? Do you mean the threshold of the door ? The door itself ? Swinging door or sliding door ? A picture would help people here answer this better for you. From what you have said- it is going to be either some super duper-caulking with questionable long term durability or removal of the concrete patio.
    – Kyle
    May 7 at 3:50
  • Let me try a photo
    – Evan Magee
    May 7 at 4:11
  • Photo is a max of 2 mb! Flush with the threshold.
    – Evan Magee
    May 7 at 4:20
  • What about a diamond cup wheel to shave 2 inches off the surface? Also it is a swinging door.
    – Evan Magee
    May 7 at 4:26
  • 1
    Yeah you need to put a bubble level on the slab to check which way the slope goes... I hope it goes in the right direction!
    – bobflux
    May 7 at 10:57

1 Answer 1


There are quite a few options in the realm of "drive way" drains as pictured below. If you have a place to drain the water to it might work.This would be installed just outside the door. You'd have to have someone with a concrete saw cut in the groove for the channel. Hopefully the slab isn't too thick. Then install the channel, draining to a low spot. Whether this is a solution for you depends upon if you can live with the aesthetics and if you have a lower place you can drain the water to. Product recommendations are off topic here, but you can do some simple searches on google for driveway drains and go from there.

driveway drain

  • Wouldn't a thicker slab actually be beneficial here? That would give room to cut the trench into the concrete and embed the drain channel without actually breaking all the way through or significantly weakening it. Unless you're intending that the channel sit directly on the dirt below the slab. (Based on the evidence that the 'friend' didn't really know what he was doing, I'm assuming that a proper base wasn't actually prepared.)
    – FreeMan
    May 7 at 12:29
  • @FreeMan I was thinking: OK they've cut 2 slots in the concrete, how are you going to bust out the middle part if it's still part of the slab? I think it would be easier to fully cut thru the slab, bust out the freed portion and, if needed pour some concrete into the groove to make it the right height to accommodate the driveway drain. Just my opinion. Thanks for your comment. May 7 at 15:28
  • I was thinking a "wood approach". Cut the edges, then multiple passes through the middle, then cold-chisel out the bits in between. I'm sure either would work, depending on the thickness of the concrete.
    – FreeMan
    May 7 at 16:05
  • @FreeMan OK, I get that idea, I've done that with wood, but that's a LOT of cutting thru concrete. Your method might also leave a pretty rough service that might need to be filled. I'm not sure, never having done this before....but I still think the best way is to make 2 saw cuts deep enough to get thru the slab, bust it up a bit and pry the chunks out (hopefully no re-bar), level the bottom with poured concrete at the right level to account for the depth of the channel. Maybe even install the channel before the concrete sets. I'd use pretty fine concrete to avoid hangups. May 7 at 20:34

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